Differences In Left Ventricular Structure And Function In Elite Aquatic Sport Athletes

Abstract

The human heart undergoes phenotypic remodelling under high-volume or pressure stimuli, resulting in sport specific adaptations. Elite swimmers (SW), who primarily endure volume-stress in aerobic training, demonstrate similar cardiac morphology to elite runners; yet reduced early diastolic function, possibly resulting from prone postures and hydrostatic pressure in training. While water polo players (WP) and artistic swimmers (AS) face similar postural and environmental stressors as SW, they also experience intermittent high-intensity bouts and breath-holds, exposing them to elevated pressure-stress. PURPOSE: To assess left ventricular (LV) structure and function, and the response to an acute pressure challenge using isometric handgrip exercise, across elite aquatic sport athletes participating in the 2019 FINA World Championships. METHODS: LV dimensions, resting systolic and diastolic function, and function during a 3 min 30% max isometric handgrip exercise were assessed via echocardiography in 30 WP (F:9, M:21), 23 AS (all F), and 37 SW (F:17, M:20) athletes. RESULTS: WP athletes displayed the greatest concentric remodelling, with female WP (6.80 ± 1.24 g/ml2/3) having a larger concentricity index than AS (5.52 ± 1.08 g/ml2/3, p = 0.02), but not SW (6.74 ± 1.45 g/ml2/3, p = 1.0). In males, WP (8.28 ± 1.32 g/ml2/3) had greater concentricity than SW (7.44 ± 0.95 g/ml2/3, p = 0.03). Diastolic function differed between sports, with SW displaying greater E/A ratio than other groups across both sexes. During handgrip, female WP augmented systolic blood pressure from rest (∆20 ± 16 mmHg) compared to AS (∆9 ± 9 mmHg, p = 0.048), and SW (∆8 ± 11 mmHg, p = 0.04), while male WP and SW responses were equivalent (∆27 ± 11 vs ∆27 ± 17 mmHg, p = 0.95). E/A ratio was unchanged with handgrip in AS (∆-0.2 ± 0.7), compared to reductions in female WP (∆-1.2 ± 0.5, p = 0.03) and SW (∆-0.8 ± 0.6, p = 0.001), and was reduced similarly in males (WP ∆-0.3 ± 0.4; SW ∆-0.7 ± 0.8, p = 0.13). CONCLUSIONS: Aquatic athletes demonstrate sport specific cardiac adaptations. While WP and SW both experience similar environmental stressors, WP show greater pressure-related adaptations of the heart, while SW show greater volume-related adaptations. AS have less structural adaptation than WP and SW, but show preservation of diastolic function with handgrip exercise.